Silt (Sludge) Test Tank: A platform for nautical bottom rheology research to optimize in-situ measurement tools and reduce dredging activities

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Colin Pierce
8 years ago
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1 Silt (Sludge) Test Tank: A platform for nautical bottom rheology research to optimize in-situ measurement tools and reduce dredging activities Stijn Claeys, Thomas Van Hoestenberghe, Jan De Schutter, Frank Mostaert 6-9 April 7th International SedNet event Maritime Access

activities Stijn Claeys, Thomas Van Hoestenberghe, Jan De Schutter,

2 In situ??: (almost) not possible(depth reference; wave; current, ) Goal 1 Goal 2 Goal 3 Testing/calibrating/ checking In-situ sensors * Nautical bottom detection (density; rheology) * Multi-parameter sensor from water column to mud column?? * Other?? Conditioning mud Fluidising (noncontaminated) mud Different dredging approach No relocation! No dilution with oxygen rich water! Stirring: breaking flock structure! Sediment barier! Other research: * flocculation study * Navigability of mud: nautical bottom Physical model: no scale model! 2D & 3D body towing => feeding CFD model

detection (density; rheology) * Multi-parameter sensor from water column to mud column?? * Other?

3 * Nautical bottom detection (density; rheology) Goal 1 Testing/calibrating/ checking In-situ sensors Top of sludge ; echosounder => 210 khz * Multi-parameter sensor from water column to mud column: feasible? Fluid mud Consolidated mud Hard bottom : echosounder => 33 khz (density 1.35 t/m³) Nautical bottom level (1) Density: (e.g.) 1.2 t/m³ Rheology (Thixotrophy) Sometimes a local relation --- Yoghurt before/after stirring * A vessel feels the resistance: rheology => CFD

Fluid mud Consolidated mud Hard bottom : echosounder => 33 khz (density 1.

4 * Nautical bottom detection Density & rheology (thixotrophy!!) Mechanical Acoustical Goal 1 Testing/calibrating/ checking In-situ sensors Gamma Instruments: -Densitune/Rheotune -Mechanical In-situ Rheometer (MIR) -Navitracker (I, 2011 ) -DART -Rheocable / Acceleroprobe - DRDP/Admodus USP -... Measuring principles Sampling & laboratory Optical Cooperation / nautical bottom research: -Ports: Deurganckdock (BE); Zeebrugge (BE); Rotterdam (NL); Delfzijl(NL); Harlinger(NL); Emden (DE); Deurganckdock (BE); Zeebrugge (BE) -Organisations: Flemish Government (Maritime Access; MDK) (BE); Port of Rotterdam (NL); RWS (NL); Grieser& Partner (DE); A. Wurpts(DE); Wiertsema & Partners (NL)...

2011 ) -DART -Rheocable / Acceleroprobe - DRDP/Admodus USP -.

5 Goal 2 Conditioning mud => Fluidising ( non-contaminated ) mud Different dredging approach Reducing dredging costs Environmentally safe? No relocation! No dilution with oxygen rich water! Sediment barrier! Stirring: breaking flock structure! No transport cost/spill! No oxygen depletion in water column / contaminant mobility? Reducing siltation / keeping sediment in river Other dredging technique 1 x month! =f(consolidation time) Cost reduction of 80% CASE Study/Reality => Emden harbour => feasibility?????

No transport cost/spill! No oxygen depletion in water column / contaminant mobility?

6 Goal 3 Other research: * flocculation study * Navigability of mud: nautical bottom

7 Goal 1 Goal 2 Goal 3 Goal Natural dredged mud! => no scale model Simulation of insitu conditions: -Suspension -Sedimentation -Consolidation -Biology (Barnacles ) Water & mud column Silt (Sludge) Test Tank STT Re-use; recycle the sludge Creating different mud Flanders Hydraulic Research Sedimentological Laboratory KULeuven Micro-biology (EPS/slimes) Phd: Stijn Claeys Sediment related Nautical Bottom: website! Properties of the Sludge Test Tank (STT) Towing and profiling sensors/bodies Conditioning (mixing/pumping/ vibrating/oxidising / of the sludge

(Sludge) Test Tank STT Re-use; recycle the sludge Creating different mud Flanders Hydraulic Research Sedimentological Laboratory KULeuven

8 Conditioning + research -Simulation of -Sedimentation -Coagulation -Flocculation -Consolidation -Conditioning: -Biology (reduce/increase activity): anaerobe/ aerobe -Reducing evaporation -Mineralogy -separation of fractions -distribution of grain sizes -Adding fractions -Chemistry (Ph; oxygen; nutrients etc..)

$fractions -distribution of grain sizes -Adding fractions -Chemistry (Ph;$

9 Gas cleaner: odour Sludge selection reservoir Pump reservoir Hydro cyclone Bridge with mixing/jetting device Aeration Sampling and observation

10 Sampling and observation Pump reservoir Bridge Aeration Hydro cyclone Sludge selection reservoir Gas cleaner: odour

12 Sampling and measurements Van Veen Grab Beekersampler Piëzo meters Observation window Sampling taps

Nautical Bottom How to keep mud under control

Nautical Bottom How to keep mud under control Seminário Internacional em Portos e Hidrovias Rio de Janeiro 11 sep 2014 Joris Vanlede Flanders Hydraulics Research joris.vanlede@mow.vlaanderen.be Zeebrugge